Copper sulfate build up on copper heatsink?

I came home from a vacation to find my computer conpletely dead, im assuming it's lightning from major storms that rocked south ontario last week.

I have noticed that I have deposits of copper sulfate on my copper heat sink and cpu cooler made by zalman. I am wondering what would cause this. Im sure it must be bad because I know it builds up on car batteries. Anyone know why I would be getting this copper sulfate? I googled it and could not find any related posts.

My apologies it was a false assumption, must have got the names mixed up for the stuff on the car battieries. I was certainly not expecting any type of oxidation or wethering to occur on a heatsink over a year so I came up with some half baked idea that maybe it was a result of a short which occured sometime during the 2 weeks I was away. I dunno. Thanks for setting me straight.